There is a rapidly growing trend toward mobile and remote data access over high-speed communication networks, such as provided by third generation (3G) or fourth generation (4G) cellular services. For example, using these services, users now rely on their smartphones for texting, access to email, banking, and social media, and for sending and receiving pictures and video.
Typically, wireless network performance depends in part on the quality of the transmission channel. For example, if the channel conditions are good, the network may perform with higher speed and capacity than when the channel conditions are poor. To obtain the best network performance, wireless networks may rely on user devices (e.g., user equipment “UE”) to report control information back to the network. The control information includes parameters indicating the channel conditions and/or transmission parameters. One mechanism available to user devices to report control information back to the network is through a physical uplink shared control channel (PUSCH). The network receives the control information over this channel and uses the received parameters to adjust data transmissions for optimum performance based on the network conditions indicated by the received parameters.
The PUSCH carries important uplink control information (UCI), including a Channel Quality Indicator (CQI), a Rank Indicator (RI), and a Hybrid Automatic Repeat Request Acknowledge (HARQ-ACK). The performance of ACK messages play an important role in the overall downlink performance as the residual error rate of HARQ is in the same order of the feedback error rate of the ACK bits. The CQI information represents the recommended modulation scheme and coding rate to be used for downlink transmissions. Its accuracy greatly impacts the overall system throughput that can be achieved in a noisy channel. Thus, improving the error performance of both CQI and ACK detection is desirable to the achieve improved network throughput.
However, there exists a tradeoff between allocating resources for the control information and the resources reserved for data transmission. Typically, the more resources allocated to the control information, the better control information decoding performance. On the other hand, the resources allocated to the information are competing with the available resource and achievable throughput for the uplink data. It is desirable to increase the decoding performance of the control bits without sacrificing the resource that can be allocated to the data portion. Yet, more advanced decoding should introduce minimum complexity and latency.
Therefore, it is desirable to have a detection mechanism that efficiently detects with high probability, control bit information transmitted from user equipment over a PUSCH.